Urethral strictures are a common problem in the practice of urology. Some of the strictures are considered “soft” and respond easily to dilation with sounds or bougies as noted in the text “Campbell's Urology”, 8th edition, page 3919. The procedure involves the passage of serially increasing size rods to the desired diameter. Other strictures are categorized as “hard” and are more resistant to plain dilation, requiring actual cutting of hard fibrous bands transurethrally.
Current optical or nonvisual urethrotomes allow for the cutting of these difficult strictures under anesthesia. The ultimate goal is for the larger lumen of the urethra to heal in the open position. One such device described by W. E. Washburn, U.S. Pat. No. 762,366, has a sheath containing a mechanical dilating head and a retractable blade, which can be used to cut the scar within the urethra in a blind fashion. There are other urethrortome-dilator combinations, which can stretch as well as cut the scar, like the Otis Urethrotome (V. Mueller Catalog). This is a mechanical device with a knob controlling the expandable portion of the instrument and a channel guide for insertion of a sharp blade, which can slide in its track and cut scar tissue in a blind fashion.
One significant disadvantage to these instruments are their “blind nature”, which can lead to complications like bleeding as well as more infrequent injuries, when the cuts are deeper than intended, and can affect erectile function and possibly incontinence if the sphincter area is traumatized. A direct vision urethrotome was developed by Sachse to allow cutting of strictures under vision (J R Soc Med 1978 August; 71(8) 596-599). The Sachse urethrotome allows for better control of the depth and extent of the incision of the cutting blade by visual observation. The instrument has a sheath, which allows for an endoscopic viewing lens, a light source, as well as a working element, which controls the blade.
However, the surgical instruments described above are typically made from multiple components, and mechanical interlocking gears or junctions. For example, blade-equipped urethrotomes for cutting tissue typically use gears and junctions to enable a medical professional to pull a trigger that exposes the blade when he or she attempts to cut tissue. Because of the numerous components typically needed to provide both cutting and stretching functionality to a urethrotome, such instruments are typically cumbersome to use and maintain. Further, urethrotomes are not typically built with an integrally formed exposed blade because of the risk of unintentionally cutting or damaging tissue.
Accordingly, what is needed are systems and methods for providing a urethrotome capable of both dilating and cutting urethral tissue, and that is inexpensive and simple to maintain.